An armor cable is commonly used in difficult environments such as in sewers to resist damage from rats. The armor tube, which is commonly electrically grounded, enables resilient bending only to very large radius of curvature. In some applications, a connector is required for connecting an end of an armor cable to a cabinet assembly, where the cable may be bent up to 90xc2x0 within a length of less than one foot. Such cables may include up to 216 wires, and it is important to avoid damage to those wires at the outside of such a bend. The armor cable is often pressurized, as with dry air or nitrogen at 15 psi above atmospheric pressure to keep out moisture and prevent corrosion. When a connector at the end of the cable is to be mated to a corresponding connector on the cabinet, such connections are commonly made in difficult environments and it is desirable to provide an indication to the technician when he has fully mated the two connectors.
In accordance with one embodiment of the present invention, a combination of connector and cable is provided, where the cable has a steel tube around dozens of wires and where the combination must allow for bending of up to 90xc2x0 within a space with a length of one foot. The armor is stripped away to leave wire front portions that are uncovered by the armor and that extend to contacts of the connector. A flexible polymer overmold is molded around the uncovered wire portions to protect them and allow for bending. The wire front portions are twisted at least one full turn and preferably more, about the cable axis prior to molding of the overmold. The twisting of the wires results in wires near the outside of the bundle, subjected to much less tension when the overmold with wires therein is bent by 90xc2x0 about a moderate radius of curvature that is less than one foot.
The overmold has a plurality of radially-outward projecting flanges that are closely spaced along the length of the overmold. The flanges are constructed to stack against one another at the inside of a bend of predetermined radius of curvature that is less than the length of the uncovered wire portions and at least about twice the outside diameter of the overmold.
A wire mesh braiding is provided which has a rear end clamped and soldered around the front end of the armor jacket portion and having a front end that is clamped around a body of the connector. Most of the length of the braiding has a diameter about equal to the outside diameter of the armor tube, but the front end of the braiding has a diameter at least 150% as great. A front portion of the braiding is pulled tight into a cone shape prior to the overmolding.
A valve is mounted on the connector to enable pressurization of the cable. The valve includes a valve element such as a ball lying in a passage of the body of the connector and spring biased forwardly. The second connector device on a cabinet has a projecting pipe that pushes the valve member rearwardly during mating to connect pressure in the second connector to the pressure within the cable.
The mating connectors have shells that are threadably connected and that form a latching mechanism that indicates when the shells have been fully threaded together and that resist unlatching. One shell which forms a coupling ring, has a front edge with multiple teeth while the other shell has a rearward projection lying on a beam that can be axially deflected. As a full threading connection is approached, the teeth brush across the projection while flicking it progressively more forcefully.
The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings.